"Every day was just a gig and I think we did the recording between gigs. We did the whole album in two afternoons, and by the end of the week we were playing the stuff on stage. That’s how wonderful it was in those days."

But during recording sessions for the I Can't Explain single, there was some pressure from producer Shel Talmy, who didn't think guitarist Pete Townshend's playing was up to scratch. As a result, Page was brought in to the record the track. Talmy also insisted on bringing in The Ivy League to record backing vocals.

Daltrey adds: "Shel Talmy didn’t think that Pete’s lead guitar playing was up to it and he didn’t think our backing vocals were up to it. He was right about the backing vocals.

"And obviously in those days you weren’t in overdub facilities. You made the record and that was it. So if you wanted to put a solo on, you had to do it when you were doing the record."

Daltrey and Townshend also discuss their notorious appearance on US TV's The Smothers Brothers Show in 1968, when Keith Moon took the stage show a little too far.